Concept:The Vedas are the earliest religious texts of Hinduism, with the Rigveda being the oldest and first literary source.
Explanation:There are four Vedas: Rigveda, Samveda, Yajurveda, and Atharvaveda.
The Rigveda is the most ancient and important Veda. It is divided into 10 mandalas (books).
It contains hymns, the Gayatri mantra, and the Purusha Sukta which explains the four varnas.
The first and tenth mandalas are the youngest and longest. Mandala 9 is devoted to Soma.
The Nasadiya Sukta in the tenth mandala discusses the origin of the universe.
The other Vedas have different focuses: Yajurveda on sacrificial formulas, Samveda on music, and Atharvaveda on Ayurveda and spells.
Because the Rigveda is the earliest known text, it is considered the first literacy source.
Answer:A. Rigveda